diff --git a/TODO.org b/TODO.org
index b3eb5f76..3a2c14d5 100644
--- a/TODO.org
+++ b/TODO.org
@@ -1264,7 +1264,8 @@ live bytes, 0 for none, that a =retry= handler raises. The failure bullet says
 "raises the allocator's budget" where it said "grows the arena", since no arena
 grows. A growable arena is not ruled out; nothing here asks for one.
 
-** TODO The Vec header is not the size the spec fixes
+** NEXT The Vec header is not the size the spec fixes
+Decided 2026-09-25: five words in every build, the epoch included, so a release build still traps on a container whose region was released. The spec changes to match the code; nothing else does.
 Five words in every build rather than the spec's four, and for a stated reason: a
 redefinition module is built separately from its host and nothing makes the two
 agree on a struct size. Give the reload path a way to carry the build flags and